Ancient History

[Dirk Wright]

On Tue, 3 Sep 1996, Tony Bryant wrote:
> >
>  
> What I want to know, is what happens when you have radical
> cam timing? This nice puddle of fuel on the inlet valve
> gets blown back up the inlet duct when the valve opens?
> Makes nice flames, if you don't run an air cleaner :-) 
> But this surely can't make for repeatable fuel volume supplied
> to the cylinder?

As Ralph pointed out, the vacuum goes down at lower rpm due to valve 
overlap. A vacuum responsive FI would make the mixture too rich for the 
engine to run. I think carburators are more tolerant of this low vacuum 
at low rpm because they are passive devices and because they are less 
precise in fuel metering.


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Dirk Wright 					            wright at uspto.gov
"I speak for myself and not my employer."               1974 Porsche 914 2.0
"A real hifi glows in the dark and has horns."            1965 Goodman House
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